The Checklist Manifesto (5 page)

On October 30, 1935, at Wright Air Field in Dayton, Ohio, the U.S. Army Air Corps held a flight competition for airplane manufacturers vying to build the military’s next-generation long-range bomber. It wasn’t supposed to be much of a competition. In early evaluations, the Boeing Corporation’s gleaming aluminum-alloy Model 299 had trounced the designs of Martin and Douglas. Boeing’s plane could carry five times as many bombs as the army had requested; it could fly faster than previous bombers and almost twice as far. A Seattle newspaperman who had glimpsed the plane on a test flight over his city called it the “flying fortress,” and the name stuck. The flight “competition,” according to the military historian Phillip Meilinger, was regarded as a mere formality. The army planned to order at least sixty-five of the aircraft.

A small crowd of army brass and manufacturing executives watched as the Model 299 test plane taxied onto the runway. It was sleek and impressive, with a 103-foot wingspan and four engines jutting out from the wings, rather than the usual two. The plane roared down the tarmac, lifted off smoothly, and climbed sharply to three hundred feet. Then it stalled, turned on one wing, and crashed in a fiery explosion. Two of the five crew members died, including the pilot, Major Ployer P. Hill.

An investigation revealed that nothing mechanical had gone wrong. The crash had been due to “pilot error,” the report said. Substantially more complex than previous aircraft, the new plane required the pilot to attend to the four engines, each with its own oil-fuel mix, the retractable landing gear, the wing flaps, electric trim tabs that needed adjustment to maintain stability at different airspeeds, and constant-speed propellers whose pitch had to be regulated with hydraulic controls, among other features. While doing all this, Hill had forgotten to release a new locking mechanism on the elevator and rudder controls. The Boeing model was deemed, as a newspaper put it, “too much airplane for one man to fly.” The army air corps declared Douglas’s smaller design the winner. Boeing nearly went bankrupt.

Still, the army purchased a few aircraft from Boeing as test planes, and some insiders remained convinced that the aircraft was flyable. So a group of test pilots got together and considered what to do.

What they decided
not
to do was almost as interesting as what they actually did. They did not require Model 299 pilots to undergo longer training. It was hard to imagine having more experience and expertise than Major Hill, who had been the air corps’ chief of flight testing. Instead, they came up with an ingeniously
simple approach: they created a pilot’s checklist. Its mere existence indicated how far aeronautics had advanced. In the early years of flight, getting an aircraft into the air might have been nerve-racking but it was hardly complex. Using a checklist for takeoff would no more have occurred to a pilot than to a driver backing a car out of the garage. But flying this new plane was too complicated to be left to the memory of any one person, however expert.

The test pilots made their list simple, brief, and to the point—short enough to fit on an index card, with step-by-step checks for takeoff, flight, landing, and taxiing. It had the kind of stuff that all pilots know to do. They check that the brakes are released, that the instruments are set, that the door and windows are closed, that the elevator controls are unlocked—dumb stuff. You wouldn’t think it would make that much difference. But with the checklist in hand, the pilots went on to fly the Model 299 a total of 1.8 million miles without one accident. The army ultimately ordered almost thirteen thousand of the aircraft, which it dubbed the B-17. And, because flying the behemoth was now possible, the army gained a decisive air advantage in the Second World War, enabling its devastating bombing campaign across Nazi Germany.

Much of our work today has entered its own B-17 phase. Substantial parts of what software designers, financial managers, firefighters, police officers, lawyers, and most certainly clinicians do are now too complex for them to carry out reliably from memory alone. Multiple fields, in other words, have become too much airplane for one person to fly.

Yet it is far from obvious that something as simple as a checklist could be of substantial help. We may admit that errors and oversights
occur—even devastating ones. But we believe our jobs are too complicated to reduce to a checklist. Sick people, for instance, are phenomenally more various than airplanes. A study of forty-one thousand trauma patients in the state of Pennsylvania—just trauma patients—found that they had 1,224 different injury-related diagnoses in 32,261 unique combinations. That’s like having 32,261 kinds of airplane to land. Mapping out the proper steps for every case is not possible, and physicians have been skeptical that a piece of paper with a bunch of little boxes would improve matters.

But we have had glimmers that it might, at least in some corners. What, for instance, are the vital signs that every hospital records if not a kind of checklist? Comprised of four physiological data points—body temperature, pulse, blood pressure, and respiratory rate—they give health professionals a basic picture of how sick a person is. Missing one of these measures can be dangerous, we’ve learned. Maybe three of them seem normal—the patient looks good, actually—and you’re inclined to say, “Eh, she’s fine, send her home.” But perhaps the fourth reveals a fever or low blood pressure or a galloping heart rate, and skipping it could cost a person her life.

Practitioners have had the means to measure vital signs since the early twentieth century, after the mercury thermometer became commonplace and the Russian physician Nicolai Korotkoff demonstrated how to use an inflatable sleeve and stethoscope to quantify blood pressure. But although using the four signs together as a group gauged the condition of patients more accurately than using any of them singly, clinicians did not reliably record them all.

In a complex environment, experts are up against two main
difficulties. The first is the fallibility of human memory and attention, especially when it comes to mundane, routine matters that are easily overlooked under the strain of more pressing events. (When you’ve got a patient throwing up and an upset family member asking you what’s going on, it can be easy to forget that you have not checked her pulse.) Faulty memory and distraction are a particular danger in what engineers call all-or-none processes: whether running to the store to buy ingredients for a cake, preparing an airplane for takeoff, or evaluating a sick person in the hospital, if you miss just one key thing, you might as well not have made the effort at all.

A further difficulty, just as insidious, is that people can lull themselves into skipping steps even when they remember them. In complex processes, after all, certain steps don’t
always
matter. Perhaps the elevator controls on airplanes are usually unlocked and a check is pointless most of the time. Perhaps measuring all four vital signs uncovers a worrisome issue in only one out of fifty patients. “This has never been a problem before,” people say. Until one day it is.

Checklists seem to provide protection against such failures. They remind us of the minimum necessary steps and make them explicit. They not only offer the possibility of verification but also instill a kind of discipline of higher performance. Which is precisely what happened with vital signs—though it was not doctors who deserved the credit.

The routine recording of the four vital signs did not become the norm in Western hospitals until the 1960s, when nurses embraced the idea. They designed their patient charts and forms to include the signs, essentially creating a checklist for themselves.
With all the things nurses had to do for their patients over the course of a day or night—dispense their medications, dress their wounds, troubleshoot problems—the “vitals chart” provided a way of ensuring that every six hours, or more often when nurses judged necessary, they didn’t forget to check their patient’s pulse, blood pressure, temperature, and respiration and assess exactly how the patient was doing.

In most hospitals, nurses have since added a fifth vital sign: pain, as rated by patients on a scale of one to ten. And nurses have developed yet further such bedside innovations—for example, medication timing charts and brief written care plans for every patient. No one calls these checklists but, really, that’s what they are. They have been welcomed by nursing but haven’t quite carried over into doctoring.

Charts and checklists, that’s nursing stuff—boring stuff. They are nothing that we doctors, with our extra years of training and specialization, would ever need or use.

In 2001, though, a critical care specialist at Johns Hopkins Hospital named Peter Pronovost decided to give a doctor checklist a try. He didn’t attempt to make the checklist encompass everything ICU teams might need to do in a day. He designed it to tackle just one of their hundreds of potential tasks, the one that nearly killed Anthony DeFilippo: central line infections.

On a sheet of plain paper, he plotted out the steps to take in order to avoid infections when putting in a central line. Doctors are supposed to (1) wash their hands with soap, (2) clean the patient’s skin with chlorhexidine antiseptic, (3) put sterile drapes
over the entire patient, (4) wear a mask, hat, sterile gown, and gloves, and (5) put a sterile dressing over the insertion site once the line is in. Check, check, check, check, check. These steps are no-brainers; they have been known and taught for years. So it seemed silly to make a checklist for something so obvious. Still, Pronovost asked the nurses in his ICU to observe the doctors for a month as they put lines into patients and record how often they carried out each step. In more than a third of patients, they skipped at least one.

The next month, he and his team persuaded the Johns Hopkins Hospital administration to authorize nurses to stop doctors if they saw them skipping a step on the checklist; nurses were also to ask the doctors each day whether any lines ought to be removed, so as not to leave them in longer than necessary. This was revolutionary. Nurses have always had their ways of nudging a doctor into doing the right thing, ranging from the gentle reminder (“Um, did you forget to put on your mask, doctor?”) to more forceful methods (I’ve had a nurse bodycheck me when she thought I hadn’t put enough drapes on a patient). But many nurses aren’t sure whether this is their place or whether a given measure is worth a confrontation. (Does it really matter whether a patient’s legs are draped for a line going into the chest?) The new rule made it clear: if doctors didn’t follow every step, the nurses would have backup from the administration to intervene.

For a year afterward, Pronovost and his colleagues monitored what happened. The results were so dramatic that they weren’t sure whether to believe them: the ten-day line-infection rate went from 11 percent to zero. So they followed patients for fifteen more months. Only two line infections occurred during the entire period. They calculated that, in this one hospital, the
checklist had prevented forty-three infections and eight deaths and saved two million dollars in costs.

Pronovost recruited more colleagues, and they tested some more checklists in his Johns Hopkins ICU. One aimed to ensure that nurses observed patients for pain at least once every four hours and provided timely pain medication. This reduced from 41 percent to 3 percent the likelihood of a patient’s enduring untreated pain. They tested a checklist for patients on mechanical ventilation, making sure, for instance, that doctors prescribed antacid medication to prevent stomach ulcers and that the head of each patient’s bed was propped up at least thirty degrees to stop oral secretions from going into the windpipe. The proportion of patients not receiving the recommended care dropped from 70 percent to 4 percent, the occurrence of pneumonias fell by a quarter, and twenty-one fewer patients died than in the previous year. The researchers found that simply having the doctors and nurses in the ICU create their own checklists for what they thought should be done each day improved the consistency of care to the point that the average length of patient stay in intensive care dropped by half.

These checklists accomplished what checklists elsewhere have done, Pronovost observed. They helped with memory recall and clearly set out the minimum necessary steps in a process. He was surprised to discover how often even experienced personnel failed to grasp the importance of certain precautions. In a survey of ICU staff taken before introducing the ventilator checklists, he found that half hadn’t realized that evidence strongly supported giving ventilated patients antacid medication. Checklists, he found, established a higher standard of baseline performance.

These seem, of course, ridiculously primitive insights.
Pronovost is routinely described by colleagues as “brilliant,” “inspiring,” a “genius.” He has an M.D. and a Ph.D. in public health from Johns Hopkins and is trained in emergency medicine, anesthesiology, and critical care medicine. But, really, does it take all that to figure out what anyone who has made a to-do list figured out ages ago? Well, maybe yes.

Despite his initial checklist results, takers were slow to come. He traveled around the country showing his checklists to doctors, nurses, insurers, employers—anyone who would listen. He spoke in an average of seven cities a month. But few adopted the idea.

There were various reasons. Some physicians were offended by the suggestion that they needed checklists. Others had legitimate doubts about Pronovost’s evidence. So far, he’d shown only that checklists worked in one hospital, Johns Hopkins, where the ICUs have money, plenty of staff, and Peter Pronovost walking the hallways to make sure that the idea was being properly implemented. How about in the real world—where ICU nurses and doctors are in short supply, pressed for time, overwhelmed with patients, and hardly receptive to the notion of filling out yet another piece of paper?